To find the momentum of a 76-kilogram horse running at a speed of 45 kilometers per hour, we follow these steps:
1. Convert speed from kilometers per hour to meters per second:
- Speed conversion factor: [tex]\(1 \text{ km/h} = \frac{1000 \text{ m}}{3600 \text{ s}}\)[/tex].
- Given speed: [tex]\(45 \text{ km/h} \)[/tex].
- Convert the speed:
[tex]\[
45 \text{ km/h} \times \frac{1000 \text{ m}}{3600 \text{ s}} = 12.5 \text{ m/s}
\][/tex]
2. Calculate momentum:
- Momentum ([tex]\(p\)[/tex]) is calculated using the formula:
[tex]\[
p = mv
\][/tex]
where:
- [tex]\(m\)[/tex] is the mass (76 kg)
- [tex]\(v\)[/tex] is the velocity (12.5 m/s)
- Plug in the values:
[tex]\[
p = 76 \text{ kg} \times 12.5 \text{ m/s} = 950 \text{ kg m/s}
\][/tex]
3. Select the correct answer:
- The correct momentum value calculated is 950 kilogram meters/second.
- The answer matches with:
[tex]\(D. 9.5 \times 10^2 \text{ kilogram meters/second}\)[/tex].
Therefore, the correct answer is:
[tex]\[ \boxed{D. 9.5 \times 10^2 \text{ kilogram meters/second}} \][/tex]